This application relates to improvements in rod guides, centralizers or the like for sucker rods in pumping oil wells and more particularly to rod guides causing reduced drag resistance and turbulence.
As is well known, sucker rods in pumping oil wells normally extend longitudinally through the well bore or well tubing and are reciprocated therein during the pumping operation. Since most well bores are not straight, and many are purposely drilled at an angle, the rods frequently wear against or engage the walls of the tubing during reciprocation, which creates detrimental wear on the rods and tubing.
The usual apparatus for pumping oil fluids includes a pump connected to the lower end of the tubing which is reciprocated in the barrel of the pump by the string of sucker rods. The sucker rods, or rod string, are connected to a reciprocating means for alternately pulling the string upward and then allowing the string to be moved downwardly by gravity.
Since the weight of the pumping rod string provides the force necessary to cause well fluids to flow upwardly through the tubing, if the resistance to movement of the string causes the rod string to move downward relatively slowly, the rate of production of well fluids is reduced. In addition, if the lower end portions of the rod string offer a relatively great resistance in downward movement, the weight of the upper portion of the rod string may place portions of the rod string under great compression loads, which tends to cause bending or bowing of the rod and increased abrasion against the internal surfaces of the tubing. If resistance to movement is unnecessarily high, a greater amount of energy is required to lift the string and much work is lost to fluid friction. If fluid turbulence is high, there is increased wear from particles in the fluid abrading against the rod.